Each part will give you a clue and you must solve it. This part will have several clues. Use all knowledge you have of cryptography, ciphers, past puzzles, etc. You should also use Google. This case is meant to take place in the present day, so all politicians, celebrities, places, etc. are who they are now. Please post your answers in spoiler tags.

Here's the riddle:

You get to the Four Seasons Hotel in Philadelphia at 4:31 a.m. You immediately get a key for room 109 and you head to the room. You open the door and look around. You check in the bathroom and see a horrible sight. Two unconscious men are hanging upside down. One has blonde hair and the other has black hair. You check their pulses and feel that they are both still alive. On the mirror you see a sticky note.

It reads:

One of us is Foul

The other one Is puRe

But to decode some silly meSsages

You must firsT find the towel

Pcihre +1

You look around and find a towel hanging above the toilet. You take it down and open it up. Two notes fall out.

The first one says:

Blam! The president is dead

Lost was he in the head

Over the years I hated him

Now my life is very dim

Dzwgwosdvk is coded name

Even though you must decode it one time more

The other one says:

Blam! The president is dead

Lost was he in the head

Always thinking must you be

Catching me will be tricky

Klbmsvwvm is what you must decode, using the hint that you were first told

$\begingroup$First you cut them both down and call an ambulance. Then arrest them both and have them questioned separately, telling each that I figured out the clues and know everything about them, and it will go easier if they just make a confession.$\endgroup$
– PopularIsn'tRightDec 16 '14 at 5:41

Here's the progress I've made so far; maybe someone else can add to it.

The riddle contains five capital letters not at the start of lines; these spell out the word FIRST. Also 'Pcihre' is an anagram of cipher (thanks @Sathish).

Reading the first letter of each line of the two notes shows us which one refers to which man (they spell out BLONDE and BLACK).

I've tried deciphering Dzwgwosdvk and Klbmsvwvm using Vigenere ciphers with all sorts of different keys (Pcihre, Qdjisf, FIRST, EWR Southwest A ["the hint that you were first told"], etc.). I'm also tried all Caesar shifts, even though I thought that'd probably be too easy. So far, no joy.

$\begingroup$I'm thinking more in the line of a caesar shift 20 (First cipher was 19 + 1 = 20, or -7 +1 =-6 which equates to the same thing) And then maybe shifting the letters to form a word? Because of the Pcihre hint.$\endgroup$
– LyrionDec 23 '14 at 15:05

$\begingroup$You are correct about the cipher anagram and the BLONDE and BLACK signaling each man. Good luck with the rest.$\endgroup$
– michaelpriDec 23 '14 at 18:09